I got my first pest! Arrgh! No more Live Rock!

[TangerineSpeedo]

So the other day, after lights out, i got out my little blue flashlight. I thought I saw one of my emeralds, but it scampered away pretty quick, which I though was odd because emeralds are not really known for their speed. Then a night ago, I noticed a couple of Zoa's missing in the morning, by evidence of a bare spot on one of my Zoa rocks. My first thought was one of the emeralds turned to the dark side. Last night I was determined to catch them in the act. So again I got out my penlight and spotted the little guy being suspicious. But this crab was not an emerald at all. My emeralds were doing there thing, on their rock that they never seem to move from. This guy, about the same size of an emerald, was not! I am pretty sure he is a stripped shore crab! Now I know what you’re thinking. You’re saying, "Wait that's crazy talk, how would a shore crab get in there?' Seeing that this is a tropical tank and Pachygrapsus crassipes, the striped shore crab is from the eastern pacific temperate waters. So I have a few crazy theories. 1. I somehow introduced him in one of my temperate tanks, (not the first time, they are the king of hitchhikers) and he said "enough of this cold water I am going on vacation in the tropics!" 2. He heard through the grapevine down at the shore that my tanks are awesome and called an Uber and snuck in. Or he could’ve walked it's only a few blocks. 3. Introduced as zooplankton either via collected NSW or kelp and grew up.
Either way, ordered a crab trap and we will see if it really is a Pachygrapsus crassipes.
Oh, the live rock part is just Clickbait... Live Rock is awesome!

 

[WheatToast]

So the other day, after lights out, i got out my little blue flashlight. I thought I saw one of my emeralds, but it scampered away pretty quick, which I though was odd because emeralds are not really known for their speed. Then a night ago, I noticed a couple of Zoa's missing in the morning, by evidence of a bare spot on one of my Zoa rocks. My first thought was one of the emeralds turned to the dark side. Last night I was determined to catch them in the act. So again I got out my penlight and spotted the little guy being suspicious. But this crab was not an emerald at all. My emeralds were doing there thing, on their rock that they never seem to move from. This guy, about the same size of an emerald, was not! I am pretty sure he is a stripped shore crab! Now I know what you’re thinking. You’re saying, "Wait that's crazy talk, how would a shore crab get in there?' Seeing that this is a tropical tank and Pachygrapsus crassipes, the striped shore crab is from the eastern pacific temperate waters. So I have a few crazy theories. 1. I somehow introduced him in one of my temperate tanks, (not the first time, they are the king of hitchhikers) and he said "enough of this cold water I am going on vacation in the tropics!" 2. He heard through the grapevine down at the shore that my tanks are awesome and called an Uber and snuck in. Or he could’ve walked it's only a few blocks. 3. Introduced as zooplankton either via collected NSW or kelp and grew up.
Either way, ordered a crab trap and we will see if it really is a Pachygrapsus crassipes.
Oh, the live rock part is just Clickbait... Live Rock is awesome!

Cool find! These crabs are known to be opportunistic predators, like many other crabs, and generally make for terrible tankmates so it definitely needs to go. I hope you have luck with the trap; these guys are some of the most skittish animals I've encountered in California tidepools, alongside blennies.
Interestingly, at least one of these crabs has been known to make quite the long, unexpected journey:
https://healthebay.org/one-little-lost-crab/
I have also heard of at least one example of Pachygrapsus crassipes being successfully incorporated into a reef tank, however, I'm not sure how long this was sustained:
https://www.practicalfishkeeping.co.uk/readers-visits/your-tanks-kyle-verry/
Clickbait is no bueno though; I agree live rock really doesn't deserve a bad rap.

 

[TangerineSpeedo]

Cool find! These crabs are known to be opportunistic predators, like many other crabs, and generally make for terrible tankmates so it definitely needs to go. I hope you have luck with the trap; these guys are some of the most skittish animals I've encountered in California tidepools, alongside blennies.
Interestingly, at least one of these crabs has been known to make quite the long, unexpected journey:
https://healthebay.org/one-little-lost-crab/
I have also heard of at least one example of Pachygrapsus crassipes being successfully incorporated into a reef tank, however, I'm not sure how long this was sustained:
https://www.practicalfishkeeping.co.uk/readers-visits/your-tanks-kyle-verry/
Clickbait is no bueno though; I agree live rock really doesn't deserve a bad rap.

Like I said not the first time they have hitched a ride. Yes, they run like crazy, but it seems like they find their way into whatever. On the temperate Nano's it is easy enough to take out a couple rocks and get them out. Unfortunately I have two big aquascapes in the 40g that are not convenient to remove. I think this trap will work. Probably catch a couple more things too.

 

[TangerineSpeedo]

So, last night I got my crab trap. its basically a acrylic box with a swinging door that is supposed to be one way. I put a piece of shrimp in there and waited and waited. Nothing so I went to bed. About 4am I got up to get some water and check on the trap, sure enough, he was in there! So still being half asleep, I decided to just wait til the morning. Guess what! the clever guy escaped! Arrgh!

 

[davidcalgary29]

Pics or it didn't happen.

 

[TangerineSpeedo]

Pics or it didn't happen.

Trying again tonight... spicing it up with a combo plate... Shrimp and Tilapia... Did this just before lights out. An hour later got out the pen light and caught him circling. He is fast... he scattered across the DT quick... like a bunny! In fact that is his new name... Bunny the crab!

 

[bnord]

Let’s see it captured too - smile

 

[d2mini]

Other than the usual gorilla crab, this was the only real S.O.B. of a crab I ever had to deal with that hitchhiked in on some really big, old live rock. He was yuuuggge. Probably a good 2" across. Stone Crab I believe.
This is him in my garden rock after he was evicted. lol

 

[TangerineSpeedo]

I failed again, He went near it last night, but didn’t check in. I don't think he is wary of the trap or too clever, but I might have to rethink the trap or the food. Maybe a mussel or oyster, something with a smell he can't resist.

 

[Tired]

You ever catch him? I'm curious what he is/was.

Make sure to kill him humanely, if you can't find a home for him. Clove oil, or something along the lines of pithing. It's not his fault he's turned up in your tank.

 

[TangerineSpeedo]

You ever catch him? I'm curious what he is/was.

Make sure to kill him humanely, if you can't find a home for him. Clove oil, or something along the lines of pithing. It's not his fault he's turned up in your tank.

No he/she is still in there. Keeping a close watch... so far just picking at detritus/algae on the rocks. I can't really ID him yet as far as the coloring because I am using a colored light at night. The reason I haven’t pulled him out yet because he/she will go in a new tank or back to the shore if it is a local. Since right now he hasn’t been a problem so he/she is fine.

 

[Tired]

Unless everything in that tank has come from the place you'd be releasing him, you shouldn't release him- there's a potential for pathogen transfer, particularly if anything involved is in the aquarium trade.

Cute little critter, whatever it is.

 

[anabechara]

Please update us on what happened to Bunny the crab!

 

[TangerineSpeedo]

Please update us on what happened to Bunny the crab!

Well there is a bit more discussion on my build thread. But essentially he is behaving himself so far, so he get to stay for now. If he starts to get out of line, there is a mangrove tank I just set up that has his name on it.

 

[RedoubtReef]

Pics or it didn't happen.

edit

 

[Tired]

Cute lil guy. Kinda looks like a shore crab of some sort to me. Can you arrange something that pokes out of the water, see if it climbs up there?

 

[TangerineSpeedo]

Cute lil guy. Kinda looks like a shore crab of some sort to me. Can you arrange something that pokes out of the water, see if it climbs up there?

I agree... I think he is definitely a shore crab, but from where, is the question at hand. In his current home (see my build thread) there is not a place he can climb up and out. In his new home "the mangrove tank" when it is completely ready, he will have a small island he can climb up on and out of the water.

 

[Tired]

That sounds like an excellent place for him! Lucky little guy.

 

[TangerineSpeedo]

I tried to get another photo of him today… Don’t go by color, but by the pattern. He was in the middle of the tank and he is still pretty small.